Genetic analysis of egg production traits in turkeys (Meleagris gallopavo) using a single-step genomic random regression model.

BACKGROUND Egg production traits are economically important in poultry breeding programs. Previous studies have shown that incorporating genomic data can increase the accuracy of genetic prediction of egg production. Our objective was to estimate the genetic and phenotypic parameters of such traits and compare the prediction accuracy of pedigree-based random regression best linear unbiased prediction (RR-PBLUP) and genomic single-step random regression BLUP (RR-ssGBLUP). Egg production was recorded on 7422 birds during 24 consecutive weeks from first egg laid. Hatch-week of birth by week of lay and week of lay by age at first egg were fitted as fixed effects and body weight as a covariate, while additive genetic and permanent environment effects were fitted as random effects, along with heterogeneous residual variances over 24 weeks of egg production. Predictions accuracies were compared based on two statistics: (1) the correlation between estimated breeding values and phenotypes divided by the square root of the trait heritability, and (2) the ratio of the variance of BLUP predictions of individual Mendelian sampling effects divided by one half of the estimate of the additive genetic variance. RESULTS Heritability estimates along the production trajectory obtained with RR-PBLUP ranged from 0.09 to 0.22, with higher estimates for intermediate weeks. Estimates of phenotypic correlations between weekly egg production were lower than the corresponding genetic correlation estimates. Our results indicate that genetic correlations decreased over the laying period, with the highest estimate being between traits in later weeks and the lowest between early weeks and later ages. Prediction accuracies based on the correlation-based statistic ranged from 0.11 to 0.44 for RR-PBLUP and from 0.22 to 0.57 for RR-ssGBLUP using the correlation-based statistic. The ratios of the variances of BLUP predictions of Mendelian sampling effects and one half of the additive genetic variance ranged from 0.17 to 0.26 for RR-PBLUP and from 0.17 to 0.34 for RR-ssGBLUP. Although the improvement in accuracies from RR-ssGBLUP over those from RR-PBLUP was not uniform over time for either statistic, accuracies obtained with RR-ssGBLUP were generally equal to or higher than those with RR-PBLUP. CONCLUSIONS Our findings show the potential advantage of incorporating genomic data in genetic evaluation of egg production traits using random regression models, which can contribute to the genetic improvement of egg production in turkey populations

Chitosan– Gelatin (Ch-G) Thin Membrane with Bone Marrow Mesenchymal Stem Cells (BMSCs): A New Model As A Dressing Bandage

Background and Purpose: Various methods for repairing defects and injuries such as wounds and cuts on the body have long been used. Biocompatible material into the body for the purposes of applying the Chitosan and gelatin are among them. On the other hand, recently the use and application of special cells in the bone marrow stromal stem cells (BMSCs) to produce a wide variety of growth factors and tropic factors in the healing and restoration of great concern was. Methods: In this study, a thin film of polymer solution (Ch-G) of mixture casting method, cells with BMSCs were obtained. For this purpose, cells were passage BMSCs after four steps, the thin membrane (Ch-G) were cultured. Adhesion of the BMSCs cells by inverted microscopy, the purity and the stem was examined by immunocytochemistry after the sixth day. Results: Demonstrate that the proper proliferation and apoptosis of cells during this period was low on the membrane. The results showed no significant difference between the cells on thin membranes (Ch-G) compared with the control group. Conclusion: Considering that BMSCs can easily be on thin-film cells (Ch-G), growth and reproduction are good, so it can cover the cell membrane as a dressing Adhesive Bandage to repair some defects, wounds used and bone fractures

Investigating Effects of Gelatin-Chitosan Film on Culture of Bone Marrow Stromal Cells in Rat

Introduction: Gelatin and Chitosan are known as biodegradable and biocompatible biopolymers. These biopolymers have recently received increasingly more attention for tissue engineering. The aim of this study was to survey of effects of Gelatin-Chitosan film in viability, proliferation, apoptosis and differentiation on bone marrow stromal cell (BMSCs) culture in rat. Methods: Fist, gelatin- chitosan composites film were prepared by solution mixing , of both biopolymer in %75 acetic acid. After two passage of BMSCs culture, cells in the four groups including control, gelatin, chitosan and chitosan-gelatin were grown. The cells viability during the second, fourth and sixth days by tripanblue, proliferation by cell account and cell apoptosis by Acridin Orange were examined. Also cell differentiation during the second, fourth and sixth day were evaluated by immunocytochemistry . Results: The results showed significant reduction in cell proliferation in chitosan alone group (P<0.05). But the gelatin and chitosan-gelatin groups were similar to the control group as the cell proliferation was increased. Also all groups had no cell differentiation. Conclusion: Results of proliferation,differentiation and apoptosis cultured BMSCs on a gelatin-chitosan film showed that gelatin-chitosan film can be used as a good model of a biodegradable scaffold in tissue engineering and cell therapy

Genetic parameters for clutch and broodiness traits in turkeys (Meleagris Gallopavo) and their relationship with body weight and egg production

The objective of this study was to estimate phenotypic and genetic parameters for clutch and broodiness (BR) traits in turkeys and their relationship with body weight and egg production. Data on dam line hens was available and included: body weight at 18 wk of age (BW18), body weight at lighting (BWL, 29 to 33 wk), age at first egg (AFE), egg number (EN), rate of lay (RL), clutch length (CL), maximum clutch length (MCL), pause length (PL), maximum PL (MPL) and BR. BR was defined as the average number of consecutive pause days between clutches that was higher than the average PL per hen. Heritability estimates for BW18 and BWL were 0.50 and 0.53, respectively. The heritability for egg production, clutch, and pause traits varied from low (MPL = 0.15; BR = 0.15) to moderate (AFE = 0.22; EN = 0.28; RL = 0.29; CL = 0.21; MCL = 0.27; PL = 0.25). Genetic correlations were negative between body weight traits and EN (rg (BW18, EN) = −0.27; rg(BWL, EN) = −0.33) and CL (rg(BW18, CL) = −0.40; rg(BWL, CL) = −0.33). BR was negatively genetically correlated with EN (rg(BR, EN) = −0.85) and CL (rg(BR, CL) = −0.30), and positively genetically correlated with PL (rg(BR, PL) = 0.93) and AFE (rg(BR, AFE) = 0.21). EN had a positive (0.73) and a negative (−0.84) genetic correlation with CL and PL, respectively. Overall, the results of this study confirmed the negative (unfavorable) correlations between egg production and body weight. Despite unfavorable genetic and phenotypic correlations between egg production traits and those relating to BR, the inclusion of BR in a selection program through incorporation of clutch length traits and pause length traits is feasible. Integration of either clutch length traits or pause length traits in a selection index is likely to increase egg number while decreasing broodiness

Genetic parameters for clutch and broodiness traits in turkeys (Meleagris Gallopavo) and their relationship with body weight and egg production

The objective of this study was to estimate phenotypic and genetic parameters for clutch and broodiness (BR) traits in turkeys and their relationship with body weight and egg production. Data on dam line hens was available and included: body weight at 18 wk of age (BW18), body weight at lighting (BWL, 29 to 33 wk), age at first egg (AFE), egg number (EN), rate of lay (RL), clutch length (CL), maximum clutch length (MCL), pause length (PL), maximum PL (MPL) and BR. BR was defined as the average number of consecutive pause days between clutches that was higher than the average PL per hen. Heritability estimates for BW18 and BWL were 0.50 and 0.53, respectively. The heritability for egg production, clutch, and pause traits varied from low (MPL = 0.15; BR = 0.15) to moderate (AFE = 0.22; EN = 0.28; RL = 0.29; CL = 0.21; MCL = 0.27; PL = 0.25). Genetic correlations were negative between body weight traits and EN (rg (BW18, EN) = −0.27; rg(BWL, EN) = −0.33) and CL (rg(BW18, CL) = −0.40; rg(BWL, CL) = −0.33). BR was negatively genetically correlated with EN (rg(BR, EN) = −0.85) and CL (rg(BR, CL) = −0.30), and positively genetically correlated with PL (rg(BR, PL) = 0.93) and AFE (rg(BR, AFE) = 0.21). EN had a positive (0.73) and a negative (−0.84) genetic correlation with CL and PL, respectively. Overall, the results of this study confirmed the negative (unfavorable) correlations between egg production and body weight. Despite unfavorable genetic and phenotypic correlations between egg production traits and those relating to BR, the inclusion of BR in a selection program through incorporation of clutch length traits and pause length traits is feasible. Integration of either clutch length traits or pause length traits in a selection index is likely to increase egg number while decreasing broodiness

Generation of focal mutations and large genomic deletions in the pancreas using inducible in vivo genome editing.

Beyond the nearly uniform presence of KRAS mutations, pancreatic cancer is increasingly recognized as a heterogeneous disease. Preclinical in vivo model systems exist, but with the advent of precision oncology, murine models with enhanced genetic flexibility are needed to functionally annotate genetic alterations found in the human malignancy. Here, we describe the generation of focal gene disruptions and large chromosomal deletions via inducible and pancreas-specific expression of Cas9 in adult mice. Experimental mice are derived on demand directly from genetically engineered embryonic stem cells, without the need for further intercrossing. To provide initial validation of our approach, we show that disruption of the E3 ubiquitin ligase Rnf43 accelerates Kras(G12D)-dependent tumourigenesis. Moreover, we demonstrate that this system can be used to rapidly interrogate the impact of complex cancer-associated alleles through the generation of a previously unstudied 1.2 megabase deletion surrounding the CDKN2A and CDKN2B tumour suppressors. Thus, our approach is capable of reproducibly generating biallelic and precise loss of large chromosomal fragments that, in conjunction with mutant Kras, leads to development of pancreatic ductal adenocarcinoma with full penetrance